std::is_signed
De cppreference.com
<metanoindex/>
<tbody> </tbody>| Definido no cabeçalho <type_traits>
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template< class T > struct is_signed; |
(desde C++11) | |
Se
T é um tipo de aritmética assinado, prevê o membro constante value true igual. Para qualquer outro tipo, é value false.Original:
If
T is a signed arithmetic type, provides the member constant value equal true. For any other type, value is false.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
Herdado de std::integral_constant
Member constants
value [estática] |
true se T is a signed arithmetic type , false contrário Original: true if T is a signed arithmetic type , false otherwise The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (membro estático público constante) |
Member functions
operator bool |
converte o objeto em bool, retorna value Original: converts the object to bool, returns value The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (função pública membro) |
Member types
Tipo
Original: Type The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
Definition |
value_type
|
bool
|
type
|
std::integral_constant<bool, value>
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Exemplo
#include <iostream>
#include <type_traits>
class A {};
enum B : int {};
enum class C : int {};
int main()
{
std::cout << std::boolalpha;
std::cout << std::is_signed<A>::value << '\n';
std::cout << std::is_signed<float>::value << '\n';
std::cout << std::is_signed<signed int>::value << '\n';
std::cout << std::is_signed<unsigned int>::value << '\n';
std::cout << std::is_signed<B>::value << '\n';
std::cout << std::is_signed<C>::value << '\n';
}
Saída:
false
true
true
false
false
false